Question

The sum of two natural numbers is 20. find the chance that their product will be less than 50?

Answer 1

do you consider 0 as natural number?

Answer 2

yes!

Answer 3

How many pairs of natural numbers add to 20?

Answer 4

21x21

Answer 5

let's see, there is 0+20 and 1+19 and 2+18 .... and 10+10

Answer 6

or i guess 21C2 .. if not repititive

Answer 7

then go through those 21 pairs and count how many of their products are less than 50

Answer 8

for now le't stick with 21 pairs

Answer 9

0 X 20 < 20, 1 X 19 < 20, ..... 10 X 10 > 20

Answer 10

21 for zero ... 20 for 1 ... 19 for two ...

Answer 11

then divide the number that multiply out > 20
by the number of pairs that add to 20
and that is the chance (probability)

a minute ago

Answer 12

for 01 and 10 is counted as same

Answer 13

you need to look at natural numbers.... not digits

Answer 14

i meant ... 0x1 make one pair while 1x0 make another pair ... if they are counted as same then we need to omit it

Answer 15

I agree,I would only take the combinations into account,
that's why I stopped at 10+10

Answer 16

14 for 3 ... 9 for 4 ... 5 for 5

Answer 17

3 for 6, 1 for 7 ... i guess rest are all used up

Answer 18

total we have 1+3+5+9+14+19+20+21 = 92

Answer 19

now it remains to determine how many unique combinations we can have for 21 numbers/

Answer 20

i guess ... 1+2+3+4+5+6+....+21 sample spaces that allows repetition and combinations

Answer 21

most likely answer will be 92/(1+2+3+ ,,,,, +21)

Answer 22

@philip513 @experimentX
>>>>>> do you consider 0 as natural number?
NO. The set of Natural numbers is the same as the set of positive integers.
The set of Whole numbers includes 0 and the positive integers.